Tuesday, April 10, 2018

[Herpetology • 2018] Peltophryne armata • A New Species of Caribbean Toad (Bufonidae, Peltophryne) from southern Hispaniola

Peltophryne armata 
Landestoy, Turner, Marion & Hedges, 2018


Peltophryne armata sp. nov. is described from the South paleoisland of Hispaniola, West Indies. This is the only native toad species known to inhabit the Barahona Peninsula, Dominican Republic, in the southernmost part of Hispaniola, and it is allopatric with the widely distributed Hispaniolan toad species, P. guentheri Cochran. However, in a molecular phylogeny, the closest relative of P. armata sp. nov. is the Puerto Rican species P. lemur Cope, with which it shares a protrusive snout, large orbits, a depressed head, indistinct or absent infraorbital crests, and a long and complex advertisement call, but differs from it greatly by the very long cephalic crests, and in the massive and spinose parotoid glands that converge medially on the dorsum. The new species is similar in ecology and larval morphology to the Cuban P. florentinoi Moreno & Rivalta, but differs from it in adult morphology. The tadpole of the new species is described. Peltophryne fracta is placed in the synonymy of P. guentheri.

Keywords: Amphibia, Anura, Caribbean, Greater Antilles, South paleoisland, West Indies, oophagy, ecomorph

FIGURE 3. Holotype of Peltophryne armata sp. nov., in dorsal (A) and ventral (B) views. Scale bars equal 5 mm. Photographs by MALT.

FIGURE 5. Crest geometry, sculpturing, cutaneous texture and shape of the head of  Peltophryne armata sp. nov. (A–B [dorsal and profile views, respectively]; MCZ A-149839), P. lemur (C–D; KU 288691), and P. guentheri (E–F; MNHNSD 23.1396). Parotoid glands are delimited by gray dashed lines. Scale bars 5 mm. Illustrations by MALT.

Peltophryne armata sp. nov.

Diagnosis. A medium-sized species of the genus Peltophryne (SVL in males to 78 mm, in females to 85.7 mm), possessing characteristics of the genus: T-shaped terminal phalanges and discrete glandular tubercles on tarsus (Fig. 4A–B, respectively; sensu Pramuk 2002), and placed within the genus in a molecular phylogeny (Fig. 2). It is distinguished from all other congeners by three unique characters: hypertrophic cephalic crests (supraorbital, postorbital, supratympanic, pretympanic and preorbital crests, the first two crests extended outwards largely covering eyelids and orbits in dorsal view; Fig. 5A–B), hypertrophic parotoid glands (longitudinally, transversely and obliquely massive) converging middorsally, and snout with a notched tip (distal ends of canthal crests create a gap in between). It is most closely related in a molecular phylogeny to the Puerto Rican species P. lemur, with which it shares a depressed head (in profile), very low or absent infraorbital crest (merged with the maxillary crest), a protrusive, slightly upturned snout, large orbits, and a long, complex (Type II) advertisement call. Beyond its unique characters, the new species also differs from that species by the geometry of crests on the dorsal surface of the head (intersection of postorbital and supraorbital crests forming obtuse angles—acute with canthal—versus these crests being nearly continuous and straight to slightly concave in P. lemur; Fig. 5C), by having the head rounded (versus subtriangular in P. lemur), by having the parotoid glands with spinose keratinized tubercles (versus subrounded keratinized tubercles in P. lemur), by having feet basally webbed (versus strongly webbed in P. lemur), and in having a large vocal sac (versus small to moderate in P. lemur).

FIGURE 6. Map of Hispaniola (silhouetted), with the south-central section amplified, showing the type locality (star) of  Peltophryne armata sp. nov., in between the Barahona Peninsula and the southern slopes of the Sierra de Bahoruco (A). Male calling at the type locality, not collected (B), photograph by Miguel A. Landestoy T. 

(Fig. 6A). Known only from the vicinity of the type locality, south of Las Mercedes in the southern slopes of the Sierra de Bahoruco north of the Barahona peninsula, Pedernales Province, bordering both the Sierra de Bahoruco and Jaragua national parks in the karst foothills (330–400 m) of the Sierra de Bahoruco.

Natural history. The habitat of Peltophryne armata sp. nov. is semideciduous forest in the limestone-based southern slopes of the Sierra de Bahoruco. Males call (Fig. 6B) next to rain water-filled holes in the limestone of mean dimensions (n=4, with eggs) of 17.2x32.5 cm in diameter and 21.9 cm in depth, where paired strings of eggs are laid and the larvae develop. One clutch contained 420 eggs. Neither amplexus nor oviposition were observed. Several males vocalized in proximity to cavities in the limestone floor where they retreated when disturbed. Two of these males experienced quick metachrosis, having a bright yellow dorsal ground color when exposed but turning brown once inside such cavities. Males MCZ A-149839 and MCZ A-149843 called in concealment from holes. Males MNHNSD-23.1376 and MCZ A-149843 performed phragmosis while hiding in such cavities, and when pushed, used their heads as shields and inflated their bodies. One individual (MNHNSD-23.1376) emitted a distress call when removal was attempted; those males and others also observed entered their respective cavities by walking backwards. All males (except MCZ A-149841 and MNHNSD-23.1375) had supraorbital crests that were injured (bleeding), missing some of the keratin and dermal tissue. This was apparently caused by the sharp surfaces of the karst substrate. The highly developed crests likely serve as a protection from the harsh environment as well as from potential predators. Individuals inflate their bodies when handled and are capable of a sudden release of air as a distress call. Skin secretions, besides those expelled from the distinctive glandular areas, are spread over dorsal surface (including eyelids) and are of a yellowish-ochre color.

FIGURE 7. Metamorph (A) of Peltophryne armata sp. nov., scale bar equals 5 mm. A toadlet (C; ~23 mm SVL) and the predominant substrate found in its habitat during the rainy season (B). Photographs by Miguel A. Landestoy T.

FIGURE 8. Tadpole of Peltophryne armata sp. nov.: profile view (A), dorsal view (B), and ventral view (C), scale bar equals 5 mm (stage 38, MNHNSD 23.1427-A). Captive live individual at stage 36, unvouchered, left for metamorphosis (D). Mouth parts (E), scale bar 1 mm (stage 37, MNHNSD 23.1425-B). Photographs by Miguel A. Landestoy T.

Etymology. The specific name is a Latin singular feminine nominative adjective meaning “armored,” in allusion to the highly developed and extended cephalic crests that cover most of the head, and to the massive parotoid glands bearing spinose keratinized tubercles.

Suggested common name. Hispaniolan Armoured Toad

Miguel A. Landestoy T., Daniel B. Turner, Angela B. Marion and S. Blair Hedges. 2018. A new species of Caribbean toad (Bufonidae, Peltophryne) from southern Hispaniola. Zootaxa. 4403(3); 523–539. DOI:  10.11646/zootaxa.4403.3.6

Resumen: Se describe una nueva especie de sapo, Peltophryne armata sp. nov., de la paleoisla sur de la Hispaniola, Indias Occidentales. Esta es la única especie de sapo nativa que habita al sur en la península de Barahona, República Dominicana, la parte más meridional de la Hispaniola, y cuya ocurrencia es alopátrica a la de la especie de sapo nativa de más amplia distribución, P. guentheri Cochran. Sin embargo, en una filogenia molecular, el pariente más cercano de P. armata sp. nov. es la especie puertorriqueña P. lemur Cope, con la cual comparte un hocico protuberante, órbitas grandes, cabeza dorsoventralmente comprimida, crestas infraorbitales débiles o ausentes, y una llamada de anuncio larga y compleja, pero difiere mucho de esta por las crestas cefálicas muy largas, y en las enormes y espinosas glándulas parotoides que coinciden en el medio del dorso. La nueva especie es similar en ecología y en morfología larvaria a la especie cubana P. florentinoi Moreno & Rivalta, pero difiere de ella en morfología del adulto. Se describe el renacuajo de la nueva especie. Peltophryne fracta es puesto en sinonimia con P. guentheri
Palabras claves: Amphibia, Anura, Caribe, Antillas Mayores, paleoisla Sur, Indias Occidentales, oofagia, ecomorfo 


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